Playing questionable words in Scrabble is a venerable tradition, originating long before Jerry’s mother threw down “quone” in an episode of “Seinfeld,” or George W. Bush offered “dignitude” against Al Gore in a 2000 “Saturday Night Live” skit. But now Hasbro, the game’s manufacturer, is offering players the chance to sneak a word into the official Scrabble Dictionary itself. The first official Scrabble Word Showdown, starting on Wednesday, allows players to nominate a new, officially playable word on its Facebook page. Contest officials will choose 16 words to face off in a March Madness-style bracket, with fans voting for their favorite. The winner will be announced on April 10 and included in the next edition of the Merriam-Webster’s Official Scrabble Players Dictionary, to be published in August.